This release of JavaHelp has the following limitations and bugs.
The JavaHelp HTML viewer is based on the Swing JEditorPane component. HTML rendering can differ depending on which version of Swing your application uses. Differences between versions are noted below.
Occasionally, images are distorted (stretched). Redisplaying the page corrects the problem.
You can sometimes avoid this problem by explicitly specifying "height" and
"width" attributes with the <img> tag. For example,
<img src="../../images/hg_note.gif" width="18"
height="13">
Due to Java security protocols, it is not possible to reference images and
files from your topics that are outside the CLASSPATH of your application
(or hsviewer).
For example, you start hsviewer with the following command:
java -jar c:\JavaHelp\demos\bin\hsviewer.jar -helpset
C:\my_app\help\myhelpset.hs
The hsviewer application sets the CLASSPATH to be:
C:\my_app\help
You cannot reference files above the C:\my_app\help folder. For example,
in the following code an image in C:\my_app\images referenced as follows
cannot be displayed:
<IMG SRC="../../images/foo.gif">
You can work around this problem by using the -classpath parameter
of hsviewer.jar. The parameter allows you to specify a CLASSPATH
separately from the helpset file, enabling you to set the CLASSPATH
to include the folder that contains the image and specify the helpset file relative
to that folder. For example, you could enter the following command (all on one
line) at the command line:
java -jar c:\JavaHelp\demos\bin\hsviewer.jar -helpset C:\my_app\help\myhelpset.hs
-classpath C:\my_app
If a TOC, or index entry points to an anchor target specified at or near the top of the page (in the first scroll zone), the viewer can position the lines incorrectly, resulting in lines' being displayed twice.
There are two problems with anchors:
The best way to work around this problem is to nest the text of the target within the anchor tag. For example:
<H2><a name="widgets">Working With Widgets</a></H2>
Tag names in styles and style sheets must be specified with lowercase letters or they will be ignored.
The <sup> <sub> tags are ignored on J2SE 1.2.2
systems.
The width attribute of the <td> tag is ignored in J2SE 1.2. That version of the viewer assigns its own width to table columns.
On J2SE 1.2.2, the width attribute works when specified in absolute pixels (px). The use of percentages (%) is not supported in that version of J2SE.
If the first item after a list tag (<ul>, <ol>,
or <dl>) is a named anchor (<a name>), the list
shown in the following example is rendered incorrectly:
<ul> <a name="17539"> </a> <li>Transmitter reports <a name="17540"> </a> <li>Channel reports </ul>The following list is rendered correctly:
<ul> <li><a name="17539">Transmitter reports</a></li> <li><a name="17540">Channel reports</a></li> </ul>
TABS used in text enclosed in <pre> tags are not recognized.
Space characters are recognized correctly.
The help viewer aborts if you attempt to load a graphic file (*.gif, *.jpg)
directly. You must include the images in an HTML file by using the <img>
tag.
Changes made to the default settings in the Page Setup dialog box are not preserved between activations. The default settings are always set upon activation.
The text search feature, implemented by running jhindexer on your helpset, has the following limitations and bugs.
The J2SE word-break iterator that the JavaHelp search indexer and search navigator use to parse Asian (Japanese, Chinese, Korean, Thai) languages uses a heuristic that is not well suited to searching. As a result, topic files are not parsed into words that users are likely to enter into the Find input field.
However, because the parser works on the same model used to highlight words when the user double-clicks in the content pane, as a workaround (albeit an inconvenient one), the Asian language user can conduct a full-text search as follows:
To enhance full-text search performance, the
search navigator reports the 100 most relevant matches.
For example, in the idedemo program, if you search for the
word "build", you see that different forms of the
word (builder, built, builds) are not highlighted because
the 100 match limit was met with the exact match "build".
This limit should not be a problem with more complex, multi-word, natural
language queries.
The jhindexer does not treat the "." character correctly.
As as result, a search for "javax.help" in the apiviewer
returns no matches.
On Solaris OpenWindows manager the F1 key does not get help on the the component with focus.
On Solaris systems, follow these steps to copy and paste text from the help viewer:
Due to a bug, the JavaTM 2 SDK jar:
protocol does not permit relative references to JAR files. Instead, they must
be fully qualified. For example, the following code works correctly:
jar:file://c:/my_app/help.jar!map.jhm
There is no way to make that reference relative from the location of a helpset file. For that reason, you must include the helpset and map files in the JAR file with the rest of the helpset.
If an index entry contains more that two hierarchical levels, a "turner" mechanism (like the one used in the TOC) is added to the second +n levels.
JavaHelp popup windows are not as accessible as they should be due to a bug in the underlying AWT classes that prevents the popups from obtaining focus. Popup windows can be dismissed by pressing the F10 key - the Esc key does not work because the window cannot obtain focus. In addition, this same bug prevents scrollbars in popup windows from being accessible from the keyboard; therefore, it is important to set the size of popups to enable all the information to be displayed in a single scroll zone.
There are limitations in this release on the ability to display fonts in the help viewer content pane. Due to a bug in the J2SE, the only character encoding that can be displayed in the HTML content pane is the system default. Different locales that use that encoding are rendered correctly. `